Improvement in ovens for firing pottery



NITED S'r THOMAS W. MINTON, OF STOKE-UPON-TRENT, ENGLAND.

IMPROVEMENT IN OVENS FOR FIRING POTTERY.

Specification forming part of Letters Patent No. l 65,855, dated July20, 1875; application filed February 6, 1874.

To all whom it may concern Be it known that I, THOMAS WILLIAM MINTON, ofStoke-upon-Trent, in the county of Stafford, England, manufacturer, asubject of the Queen of Great Britain, have invented or discovered newand useful Improvements in Ovens for Firing Pottery, Glass, and othersubstances; and l, the said THOMAS WILLIAM MINTON, do hereby declare thenature of the said invention, and in what manner the same is to beperformed, to be particularly described and ascertained in and by thefollowing statement thereof-that is to say This invention has for itsobject to improve the construction of ovens for firing pottery,

glass, and other substances.

In the ovens previously in use the fuel is burned in feeders or mouthsdisposed partly on the outer circumference of the oven, and partly underthe walls of the same, by which arrangement the greatest portion of theheat radiating from the coke, and a portion, also, of that given off bythe gases, generated by the coals, has no other effect than to heat thesurrounding brick-work without any direct action on the ware to bebaked. In the improved oven the old feeders or mouths are dispensedwith, the combustion of the coals being entirely efiected inside, or inthe hold, of this oven, so that the heat from the coke or the gases hasa more direct effect on the saggers containing the ware with which itcomes in contact; thus a considerable reduction in the quantity of fuelrequired to fire the ordinary ovens is realized. Besides, by theaddition of a second chamber on the top of the oven, use can be made ofthe heat that might escape from the lower part, for hardening theprinted ware, or firing those articles of pottery for which a low heatis necessary, avoiding the necessity of surrounding the ovens by asecond building called hovel, In this way an economy of space and moneyis effected.

In the drawings annexed, Figure l is a vertical section, and Fig. 2 asectional plan, of an oven constructed according to my invention. Figs.3, 4, and 5 show some of the parts separately.

c a are the fire-bars; b b, the doors through which the fuel issupplied; 0 c, the fire places or bags in which the combustion takesplace,

and in the lower front of which some loose bricks d are placed toprevent the coals falling in ash-pits e c. When the oven is firing, theflame produced in these bags is directed, by means of four or five opensaggers, ff, toward the upper part of the oven, and, as there is noopening in the vault through which the heat might escape, the flame iscompelled to travel in a downward direction to reach the floor g g,where a number of openings, h h, are disposed. These openings giveaccess to several horizontal flues, t i, and from these gases reach theupper chamber in passing through the upright flues j j, existing in thethickness of the walls. From the second chamber the final escape of thegases is effected by the outer chimney It. At various heights above thedoors used for the supply of coals the small openings m mm have forobject to introduce the quantity of air necessary to effect a perfectcombustion, and they are regulated according to the quality of fuel. Thecooling-flue L, which communicates outside, is kept shut all the timethe oven is firing, and is open afterward to assist in cooling. Thedamper M in the center of the vault is also removed after the firing,for the same object. Access to the upper chamber is provided by the doorN, and the brackets 0 0 0 built in the inner circumference are intendedfor placing the printed ware, which has to be hardened. Another objectof this upper chamber is to collect the gases from the upright fines jj, so that the outer chimney acting on all of them at the same timeequalizes the draft of those which might be backward or in advance. Byreducing the diameter of this outer chimney the flame may be broughtinto the second chamber, or by enlarging it a complete combustion may beeffected in the lower part of the oven, so that carbonic acid only willbe found in the upper chamber.

If, in constructing an oven, it is desired to suppress this upperchamber, the upright flues 'jj are omitted, and the gases passing in theflues t i are directed to a central opening similar to L enlarged, fromwhich they are sent to an outside chimney, which will act for several ofthese ovens.

Having thus described the nature of my P. MULLANE.

Sash-Holder.

N0 ]65,856, PatentedJuly20,1875.

(% vzmm moauns.

